## Facts

- Danny Lee Jones went to Robert Weaver’s home intending to steal Weaver’s gun collection.
- Jones killed Weaver by beating him with a baseball bat and shooting him in the head.
- Jones killed Weaver’s 7-year-old daughter, Tisha, by beating her and suffocating her.
- Jones beat Weaver’s grandmother, Katherine Gumina, leaving her permanently disabled.
- A jury convicted Jones of two counts of premeditated first-degree murder and one count of attempted premeditated murder.
- The sentencing judge found aggravating circumstances: multiple homicides, pecuniary gain, and that the murders were especially heinous, cruel, or depraved; for Tisha’s murder, the judge also found the victim was a young child.
- The sentencing judge found mitigating circumstances (long-term substance abuse, impairment at the time of the murders, head trauma, and childhood abuse) but concluded they were not sufficiently substantial to warrant leniency and imposed the death penalty.
- The Arizona Supreme Court affirmed after independently weighing aggravation and mitigation.
- In federal habeas, the district court denied relief; the Ninth Circuit granted relief on a sentencing-phase ineffective-assistance claim based on omitted mitigation evidence.

## Issues

1. In capital sentencing ineffective-assistance claims alleging omitted mitigation evidence, how should prejudice under *Strickland v. Washington* be assessed when the case is reviewed under AEDPA?
2. Did the Ninth Circuit improperly find *Strickland* prejudice by reweighing aggravating and mitigating evidence instead of asking whether the state court’s contrary conclusion was objectively unreasonable?

## Decision

- The Supreme Court reversed the Ninth Circuit and remanded.
- The Court held the Ninth Circuit’s prejudice analysis rested on an erroneous interpretation and application of *Strickland* within AEDPA’s deferential framework.
- The Court stated prejudice turns on whether it is reasonably likely the additional mitigation would have avoided a death sentence, assessed by considering the strength of all evidence and comparing aggravation and mitigation.
- Applying AEDPA, the Court concluded Jones did not show the state court’s rejection of prejudice was objectively unreasonable.
- On remand, the Ninth Circuit affirmed the district court’s denial of habeas relief.

## Legal Principles

- *Strickland* prejudice at capital sentencing requires a reasonable probability (reasonable likelihood) that, absent counsel’s errors, the sentencer would have imposed a sentence other than death.
- The prejudice inquiry requires a comparative assessment of the weight of all aggravating and mitigating evidence, including the strength of the aggravating case and the incremental value of the omitted mitigation.
- Under AEDPA, a federal habeas court may grant relief only if the state court’s application of clearly established federal law was objectively unreasonable; it may not replace a reasonable state-court weighing with its own.
- Additional mitigation evidence that is cumulative or only incrementally different from mitigation already credited by the sentencer may be insufficient to establish prejudice, particularly in the face of strong aggravating circumstances.

## Conclusion

The Court reversed habeas relief because the Ninth Circuit reweighed mitigation and aggravation rather than applying AEDPA deference to the state court’s reasonable determination that additional mitigation evidence was not reasonably likely to have changed the death sentence.


Thornell v. Jones, 144 S. Ct. 1302 (2024)